dm: Use uclass_first_device_err() where it is useful

Use this new function in places where it simplifies the code.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/timer/timer-uclass.c b/drivers/timer/timer-uclass.c
index 382c0f2..f8ddf93 100644
--- a/drivers/timer/timer-uclass.c
+++ b/drivers/timer/timer-uclass.c
@@ -82,11 +82,9 @@
 	node = fdtdec_get_chosen_node(blob, "tick-timer");
 	if (node < 0) {
 		/* No chosen timer, trying first available timer */
-		ret = uclass_first_device(UCLASS_TIMER, &dev);
+		ret = uclass_first_device_err(UCLASS_TIMER, &dev);
 		if (ret)
 			return ret;
-		if (!dev)
-			return -ENODEV;
 	} else {
 		if (uclass_get_device_by_of_offset(UCLASS_TIMER, node, &dev)) {
 			/*